Immune System is the system that consists of proteins and cells.
Answer:
B.secrete hormones directly into the bloodstream
"Substitution" is the type of mutation among the choices that are given in the question that the plant undergo. The correct option among all the options that are given in the question is the second option or the penultimate option. I hope that this is the answer that has actually come to your help.
A BMI of 18.88 would be pretty normal for a 13 year old if not a bit on the lower side already. Usually we consider a BMI between around 18/19 and around 25 to be that of a normal weight person. If it is below theis, we would recommend to eat more, if ti above this we would recommend to eat less. Considering that we're talking about a 13 year old, perhaps it would be better if he/she ate a bit more to supply his body with the necessary nutritional needs.
